21171367 has 4 divisors (see below), whose sum is σ = 24195856. Its totient is φ = 18146880.

The previous prime is 21171361. The next prime is 21171373. The reversal of 21171367 is 76317112.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21171361) and next prime (21171373).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21171367 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21171361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1512234 + ... + 1512247.

It is an arithmetic number, because the mean of its divisors is an integer number (6048964).

Almost surely, 2^21171367 is an apocalyptic number.

21171367 is a deficient number, since it is larger than the sum of its proper divisors (3024489).

21171367 is an equidigital number, since it uses as much as digits as its factorization.

21171367 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3024488.

The product of its digits is 1764, while the sum is 28.

The square root of 21171367 is about 4601.2353775915. The cubic root of 21171367 is about 276.6408435439.

Adding to 21171367 its reverse (76317112), we get a palindrome (97488479).

The spelling of 21171367 in words is "twenty-one million, one hundred seventy-one thousand, three hundred sixty-seven".